Crystal growth and cation distribution in doped dicalcium ferrite Ca2(Fe1-x Mex)2O5 (Me = Al3+,Ga3+)
Kahlenberg, Volker; Fischer, Reinhard X.
European Journal of Mineralogy Volume 12 Number 1 (2000), p. 129 - 135
published: Feb 7, 2000
manuscript accepted: Sep 22, 1999
manuscript received: Sep 13, 1999
ArtNo. ESP147051201027, Price: 29.00 €
Abstract The crystal structures of Ca2(Fe0.933 Al0.067)2O5 and Ca2(Fe0.722 Ga0.278)2O5 have been determined from single crystals grown from a CaCl2 flux. Both are isostructural with Ca2Fe2O5 (C2F), belonging to space group Pnma. Lattice constants are a = 5.420(1) Å, b = 14.743(3) Å, c = 5.597(1) Å and a = 5.420(1) Å, b = 14.721(3) Å, c = 5.599(1) Å, respectively. The Al3+ ions in the doped C2F occupy the tetrahedral 4(c) site of Pnma exclusively. In the gallium doped sample, the Ga3+ ions preferentially reside on the tetrahedral positions with a significant amount of about 23 % of the total gallium content in the octahedrally coordinated 4(a) site.